Looks like they built the relay for .85 amps and marked it for .75 amps tripping. They evidently found a problem back in 1984, but I doubt that specific issue would relate to the huge surges reported here on industial equipment and household central air conditioning unit surges, where a cheapo Lowes 5 hp might handle the surge as reported in the post above. It just has to be tested on a case by case basis.
If I ever get back on my 5KW and test, I will test it with a good running A/C that has been tested with a bigger genset. I have tested it with a military horizontal heat and air unit rated at 36K BTUs and the heat comes on but fully bogs the 5KW gen set down. The A/C compressor, when in A/C mode does not come up at all, but the fan comes on. These kinds of things cannot draw any conclusions as the A/C is not tested and verified as good, but I did find it interesting the heat would really bog down the generator. I did get good heat and there was no trip, but that heat is strip heat and resistive in nature. I need to test further to draw any conclusions, but I can almost predict accurately this gen set will not run the A/C due to the starting nature of high current on a compressor and inductive loads.
I feel, based on the posts above, and a treasure trove of information, the use of a 5KW or 10KW gen set for an inductive load provided by shop equipment, electrical motors, starting capacitors and compressors, is a misapplication of these types of gen sets. But what remains inconclusive, is what did the military engineers, who put out the spec for manufacture, have in mind, and what did the operators have for guidelines in applications in the field. Surely they were told these gen sets were not functional for industrial motors and they had this as common knowledge, and the primary useages were for low level starting or resistive current applications like lighting for tents and not for motors, where they had to have instructions to bring along a much higher rated gen set, like a 15, 30, or 60kw generator for motor startups.
It's beginning to make the cheapo 5-7.5kw lowes gas generator look more and more promising for all around useage, provided you don't need it for more then a day or two at a time without maintenance, unless you specifically need 3 phase power for non inductive loads. If anyone wants a 5kw on a trailer for sale, reasonably priced and in good condition, check the classifieds. I'll be putting mine up for sale shortly, before I go through all the aggravation of wiring it up and trying to make it work with my home A/C unit. I never planned on using it for a 3 phase power shop. Thanks for all the info guys.
